"Agreed" is the past tense of " agree ," indicating a consensus or approval that has already been reached, while " agree " is the present tense form, expressing current consent or concurrence. Agree definition: To be compatible or consistent.Origin of Agree Middle English agreen from Old French agreer from Vulgar Latin aggrātāre Latin ad- ad- Latin grātus pleasing gwerə- 2 in Indo-European roots From American Heritage Dictionary of the English Language, 5th Edition Old French agreer (“to accept or receive kindly”), from a gré (“favorably”), from Latin ad (“to”) + gratum (“pleasing”). From Wiktionary AGREEING definition: 1. present participle of agree 2. to have the same opinion: 3. to decide something together: . Learn more. Agree , the general term, suggests compliance in response to any degree of persuasion or opposition: to agree to go; to agree to a meeting, to a wish, request, demand, ultimatum.